Flexible toggle link actuated crimping tool



y 1956 c. A. BADEAU 2,743,634

FLEXIBLE TOGGLE LINK ACTUATED CRIMPING TOOL Filed 001;. 2, 1951 I Em I NV EN TOR. 634mm! A. 540.540

Aime/WV Unitd States Patent FLEXIBLE TOGGLE LINK ACTUATED CRIMPING TOOLCarroll A. Badeau, Westfield, N. .l'., nssignor to The Thomas &BetisCtL, Elizabeth, N. J., a corporation'of New Jersey ApplicationOctober 2, 1951, Serial No. 249,311 6 Claims. c1. til-15) The inventionrelates to a crimping tool of the pliers type particularly, but notexclusively, designed for use in deforming a small malleable metalsleeve. into a crimping engagement with wires within the sleeve formaking a durable joint therebetween in forming electric fittings.

The present disclosure relates to an improvement and further developmentin thetpower-multiplying toggle features of such tools as disclosed inthe ctr-pending application of Martin D. Bergen, filed herewith,entitled Crimping Tool, Serial No. 249,309, filedtOctober 2, 1951, nowPatent No, 2,696,747. The same reference characters are used in bothapplications to identify corresponding parts.

in the Bergen patent there is disclosed a squeeze clamp for deformingthe sleeve, a shiftable jaw of which clamp is powered from an actuatinghandle operating through a toggle having equal length arms to attainsuch mechanical advantage as is inherent in such mechanism, as thetoggle reaches its theoretical maximum output. The Bergan applicationdevice works satisfactorily provided the available manual-forceoperating the handles is sufiicient, when multiplied through the toggleas shown, to overcome the resistance interposed by the sleeve to thesqueezing action of the jawsthereon, and provided the resultant outputforce is sufficient and operates continuously up to the point where theshiftable jaw is able to reach its pre-set point of nearest approach tothe fixed jaw as featured in said Bergan application. It is not unusualin this art for the sleeve to resist the closing movement of the jawsduring the initial closing movement and thus before the toggle candeliver its maximum output force. j

The primary object of the invention is to provide a form of crimpingtool featuring a toggle form of mechanical advantage which will make thedesired crimp in the sleeve under all normal conditions and thus underconditions where the output force is not suificient to overcome theresistance interposed by the sleeve during the initial period of thecrimping act.

Broadly, this objective is attained by interposing a nonloaded andrelatively rigid spring in the chain of power transmitting parts betweenthe actuating handle and the relatively fixed jaw or its backing andwhich spring will operate when loaded by reason of the resistance to theclosing of the jaw to increase automatically the mechanical advantage ofthe toggle and thus change the toggle ratio sufficiently to utilize theavailable power to overcome the resistance interposed by the sleeve andthus cause the jaws to effect the desired crimp.

Various other objects and advantages of the invention will be in partobvious from an inspection of the accompanying drawings and in part willbe more fully set forth in the following particular description of oneform of crimping tool embodying the invention, and the invention alsoconsists in certain new and novel features of construction andcombination of parts hereinafter set forth and claimed. i l

2,743,634 Patented May 1, 1956 In the accompanying drawings,

Fig. 1 is a view taken along the medial central plane of a preferredembodiment of the invention showing the position of the parts at anintermediate state of the crimping operation, slightly closed from theirfully open position shown at the time the crimping jaws are be ginningto meet an opposition to closing under the force output of the toggleand in its position as shown with the slot of the spring link open andthus with the link having its normal maximum length and unloaded;

Fig. 2 is a similar view with the jaws still in their arrested positionwith the toggle considered as a whole advanced slightly from itsposition shown in Fig. 1 towards its final position, with the slot ofthe link closed and with the link, loaded and in position to be advancedslightly therefrom to its final position of nearest approach to thefixed jaw;

Fig. 3 is a plan view looking down on the left end of Fig. l; i

Fig. 4 is a view of the slotted link shown in the preceding figures inits normal unloaded condition as in Fig. l;

Figs. 5 and 6 are views of modified forms of the link shown in Fig. 4;and

Fig. 7 is a view similar to Figs. 1 and 2 of a modified form of toolwith the toggle in its dead center position, with a solid form of link,and showing in full lines a slotted form of the die forming the fixedjaw, and showing in dotted lines a slotted form of shiftable die jaw.

in the drawings there is shown a crimping tool 10 of the pliers typeused to crimp a metal sleeve S onto wire conductors C therein. The toolincludes a long main body, frame or relatively stationary member 11 anda long lever 12 pivotally connected to the member 11 at pivot pin 13 andwith member and lever provided with extensions forming, respectively, alower handle 14 and an upper handle 15 normally disposed in parallelrelation as shown in Fig. 7. An upturned solid end 16 of member 11 formsa rugged seat or backing for receiving in abutting relation thereto areplaceable die element 17 forming the relatively fixed jaw of a squeezeclamp.

A rockable link 18 pivoted to the member 11 forms a coacting die and therelatively shiftable jaw of the clamp. The shiftable jaw 18 is connectedto lever 12 by a pair of short connecting links 19 which form with ashort end of the lever a toggle connection providing a mechanicaladvantage to the system. The portion of the member 11 between the end 16and the handle 14 is slotted as shown in Fig. 3 and provides a pair ofcheek plates 20 and 21 between which cheek plates the jaw 18 and thelinks 19 are contained.

The upturned end 16 is provided on its inner side with an upstandingflat face 22 against which abuts the die element 17. An anchoring pin 27secures die 17 in place and forms a fulcrum about which rocks theshiftable jaw 18.

While it is usual to provide the jaws of a crimping tool with aplurality of matching nests and coacting indentors, only one is shown inthe accompanying drawing as being sufiicient to disclose any one of aplurality of crimping steps. For this purpose the fixed jaw is providedwith a depression or nest 29 and the shiftable jaw is provided with anindentor 30 between which the assembly of sleeve and conductors to becrimped is inserted The level 12 is fulcrumed intermediate its ends andquite close to the links 19 and has a long arm which forms the upperhandle 15, and a very short toggle element forming arm 31 which projectsfrom the pin 13 towards the shiftable jaw. The links 19 are in pairs onopposite sides of the arm 31 and the jaw 18. One end 3 of the pair oflinks is pivoted to the short arm 31 by a dowel pin 32 and the other endof the links is pivoted to the shiftable jaw 18 by a pivot pin 33.

The shiftablc jaw 18 has two limiting positions (neither of which isshown), one a fully open position at the of its operative stroke and aposition of nearest approach to but spaced slightly from the fixed jawand spaced an exact factory-pre-set distance from the fixed jaw when thetoggle has reached its dead center position.

The pins 33, 32 and 23 are shown in their positions of being insubstantially a dead center alignment on the line d'c as shown in Fig. 7at the time when the jaws are in a desired preferred spaced-apartrelation controlled by the length of the connecting links.

to this point the disclosure is exactly as described fbi the showinginthe above-identified Be'rgan application, with its fixed length oflinks.

The particular feature of novelty in this disclosure as illustrated inFigs. 1 4 is that each of the links 19 is provided with a slot 50extending transversely of the link adjacent its mid-length, and eachoutlined by a pair of parallel spaced-apart walls 51, 52 extendinginwardly from its top edge 53. The pair of links so slotted operate toform collectively a spring steel plate normally rigid and thus eachresistant to collapsing in its own plane under relatively high load, butcapable of collapsing each in its fiatwise dimension under extremelyhigh load to a new and fixed length slightly shorter than the normallength, and thus capable of modifying the toggle ratio to obtain withthe less length of connecting link a more powerful toggle action thanwould be possible if the links were not so shortened under excessiveload.

i In other words, the distance measured between the axis of the pins 32and 33 is slightly shorter in Fig. 2 than in Fig. l by air amountapproximately one-half of the width of the slot 50.

In operation and assuming a stock assembly of a sleeve 5 with wireconductors C therein is located in the nest 29 and at which time thesleeve is of tubular and usually cylindrical form, the device is readyfor operation. Bringing the hahdles together causes the indentor 30 insuccession; first to engage and then to push in the adjacent side of thesleeve and thus to deform the same, as in usual in the crimping art.During this initial squeezing operation the links 19 function as dosolid links, and this condition of the links continues so long as thepower output of the toggle mechanism is sufficient to overcome anyresistance which may be interposed by the sleeve in its resistance tobecoming further deformed.

.In further explanation let it be assumed that at some point in theadvance of the shiftable jaw 18, say, at the point shown in Fig. 1, thepower output of the toggle 3119 is not sufficient to overcome theresistance of the sleeve S at this instant, but is sufficient toovercome the resistance of the links to become deformed. At this pointthe short arm 31 of the lever 12, and with it the pin 32, continues tomove clockwise, that is, upwardly in the showing of Fig. 1 while theshiftable jaw and with it the pin 33 is held from further advance by thepartly crimped sleeve S. Eventually, with the continued and very muchrestrained action of the lever the walls 51, 52 angle inwardly and closethe outer end of the slot uiitil the walls contact at their outer edgesto form an iiite'r bearing point 501i, and thus the link along its upperportion becomes in effect a solid that is, a non-yielding,non-collapsible link of slightly shorter all-over length thanb'rigihally. With the links 19 thus shortened, even though slightly, thepower effect of the toggle is improved and in the case illustrated thetoggle can then have into or at least practically into its dead centerposition and thus into a position capable of delivering to the shiftablejaw its maximum possible power output.

The final crimping action is had by a slight further advance of theactuating handle 15 beyond the position of the parts as shown in Fig. 2and until the desired preset degree of crimping deformation of thesleeve S has been attained, as more fully defined in the companionBergan application.

For a more detailed explanation of the toggle action of the illustrateddevice, it is recalled that in the case of a toggle joint of equallength arms the multiplier used to determine the resulting maximum forceis the coefficient of the angle at any instant of time multiplied by theinput power acting on the lever. Let us assume in the case illustratedthat the in-put at the handles is fifty pounds and with the toggle at,say, twenty dgrees as in Fig. 1, a resultant force of, perhaps, 1000pounds is be ing delivered to the shiftable jaw 18. Let it be assumed,however, that this 1000 pounds is not sufiicient to further deform thesleeve, and which further deformation we will say requires a squeezeforce of 1200 pounds. This situation often occurs in crimping operationsand the operator is quite apt to assume that the crimp has beencompleted when he can close the handles no further.

Let it be further assumed in the instant case that the spring links 19are designed so that they will deflect towards their condition as shownin Fig. 2 at a force of about 800 pounds. As the width of the slotat'its outer end progressively decreases under the 1000 pounds load,there is a resultant decrease in the center-to-center distance betweenthe axes of the pins 32, 33, and the original toggle link of eqiiallength arms becomes a toggle line of unequal length of arms, and in thisway the handle 15 can be forced down towards the handle 14 an additionalnumber of degrees, say, five or more degrees as exemplified in Fig. 2.The pin 32 forming the knee of the toggle can be moved nearer to thedead center line c-d than before and the angle of twenty degrees in Fig.1 decreases to, say, fifteen degrees in Fig. 2. Of course, as the togglebegins to straighten out by reason of its momentarily overcoming theinitial resistance interposed by the sleeve, enormously powerful squeezeforces appreaching a tori or more are developed as the final squeezeforce. In this way a crimping tool having a specific and limited inputforce can by the use of spring links in its chain 'of toggle parts asherein disclosed overcome a specific resistance to the closing movementof its squeeze jaws in a way not possible with conventional forms ofsuch tools wherein the toggle parts have arms of fixed lengths, as inthe aforesaid Bergan patent.

Releasing the lever pressure permits the inherent resili'ency of thelinks 19 to restore themselves to their origithe toggle a little morefreedom of movement close to its dead center line position than ispossible with conventional forms of rigid arm toggles, it is possible toobtain this result otherwise than by following the preferred scheme ofslotting the toggle link. For instance, and referring to the modifiedform of the invention shown in Fig. 7, it will be seen thatsubstantially the same effect as was produced by a slotted link in thetoggle may be obtained by similarly slotting either the fixed or theshiftable die, or both, in planes spaced from and parallel to thegeneral direction of the work-engaging face of the die so slotted.

For this purpose the die 17 shown at the left of Fig. 7 is provided witha narrow slot 54 extending transversely through the die from edge toedge. The slot is outlined by parallel, closely related,transversely-extending walls 55, 56 extending inwardly from the upperedge 57 for the full length of the associated work face with its seriesof nests. The die 17 thus forms a pair of rigid, upstanding springplates 58, 59, with the plate 59 capable of bending at its root endresiliently towards the fixed plate 58, in the event the output from thetoggle as it approaches its dead center position is not suflicient priorto the bending of the plate to overcome the resistance ofiered by asleeve for the moment located between the work faces of the jaws of theclamp. Even the slight give provided by the slot in closing at its upperend exactly as described for the slot 50 permits the knee 32 of thetoggle to approach the dead center line c-d a little more than would bepossible if the slot 54 were not present, and thus the toggle is capableof exerting a more powerful thrust on the shiftable jaw than would bethe case if the die 17 were solid as in the Figs. 1-3 showing.

Also, in Fig. 7 the shiftable jaw 18 is provided with a slot 60 shown indotted lines formed identically as is the slot 54 and similarly forminga shiftable indentor plate 61 and a rigid backing plate 62 forming thebalance of the shiftable jaw. This form with its slotted shiftable jawoperates in identically the same way as does the slotted fixed jaw andis correspondingly operative in closing to permit the solid link toggleto approach its dead-center position when the indentor plate 61 of thejaw is momentarily stopped from further advance by a sleeve between thejaws.

Ordinarily, only one of the jaws, either the fixed jaw 17 or theshiftable jaw 18, is slotted as shown in Fig. 7, but it is suggestedthat both may be slotted in those cases where a material advance of thework faces towards each other is desired after the sleeve therebetweenbegins to demonstrate its resistance to further crimping, and it issuggested that the slot 60 may be wider than the slot 54 and in this wayeffect a progressive give to the resistances interposed by the sleeve tothe squeezing eifect thereon.

Figs. 4 and 5 are forms of links different from the preferred andsimplest form shown in Figs. 1-3, and which have been substitutedtherefor in the tool illustrated in Figs. 1 and 2 in different physicalembodiments of the invention.

Fig. 5 shows a four-eyed link 63 of four-leaf clover form provided withfour pivot holes 64, any opposing two of which may receive the pins 32and 33. Two of the holes 65, 66 are connected by a kerf 67. At oppositeedges of the link 63 kerfs 69 and 6? lead, respectively, to the othertwo holes 68 and 68'.

Fig. 6 shows an elongated form of link 70 provided with an opening 71therethrough of key-hole form having a circular recess 72 at one end andwith the other end of bifurcated form with the two sides 73, 74separated by a narrow cut 75.

In so far as the present disclosure is concerned, it may be assumed thatthe links of Figs. 5 and 6 operate as do the links of the form shown inFig. 4.

While the invention has been described in connection with a manuallyoperated type of pliers tool, it is obviously within the scope of thedisclosure to operate the toggle by mechanical power and, of course, inthis case the dies need to be carried on pivotally related jaws, but theshiftable die may approach the fixed die along a straight line in acompressive machine.

In both forms of the invention the part 16 may be considered as a frame,the lever 12 may be considered as a source of power, and the elementsbetween the source and the frame, to-wit, the toggle 3119, the shiftabledie 1% and the fixed die 1"], may be considered as a chain of squeezepressure transmitting elements, one of which, either the links 19, thedie 18 or the die 17, is slotted across the line of squeeze force toprovide the U-spring herein featured.

I claim:

1. A crimping tool including a body portion provided at one end with afixed jaw and its other end forming a handle, a coacting shiftable jawpivoted to the body portion, a lever pivoted to the body portion andcomprising a short arm and a long arm forming a handle,

a link pivoted at one end to the short arm and at its other end to theshiftable jaw to move the same to and from the fixed jaw, said short armand the link coacting to form a toggle operative to move the shiftablejaw to a position of nearest approach close to but spaced slightly fromthe fixed jaw as the toggle reaches a deadcenter position, said linkbeing slotted in the part thereof between the shiftable jaw and theshort arm, forming a normally unloaded U-shaped spring operable whendeformed under load by the further advance of the short arm in turningslightly towards its dead center position after the shiftable jaw hasbeen restrained from movement towards the fixed jaw by reason of theresistance interposed thereto by an object located between the jaws topermit the toggle as it approaches its final position to exert a squeezeeffect capable of moving the shiftable jaw to its position of nearestapproach against the re sistance interposed by the object.

2. A crimping tool including a fixed die element and a shiftable dieelement, a toggle for actuating the shiftable die element, said toggleincluding a work arm and a normally rigid link pivoted at one end to theshiftable die element and at its other end pivoted to the arm, said linkin the part thereof between its pivotal connections with the die elementand arm being slotted to form a spring link capable of shortening thenormal distance between its pivotal connections when the shiftable dieelement is restrained from further movement and the toggle continues tomove towards its dead center position.

3. A toggle including a flat steel link, pivots at its opposite endsconnecting the link to the adjacent elements of the toggle, said linkcapable'of transmitting squeeze pressures therethrough in the plane ofthe link, and said link in the portion thereof between its pivots beingslotted inwardly from one edge to form a narrow slot normally open atits outer end and capable of closing at its outer end when forcescapable of doing so cause the pivots to approach each other.

4. A toggle one of whose component elements is nor1nally rigid and isslotted to provide a normally open slot extending across the line offorce in said element and said slot being collapsible towards a closedposition under forces acting through the element capable of deformingthe same to effect such closing of the slot.

5. A mechanical movement including a shiftable work element, a togglefor actuating said element, said toggle including a work arm and a linkof spring steel pivoted at one end to the work element and at its otherend pivoted to the work arm, said link in the part thereof between itspivotal connection with the work element and the arm being slottedinwardly from one of its: edges to form the link as a U-spring.

6. In a crimping tool including two jaws operative to squeeze an articletherebetween, a chain. of connected parts including a toggle for movingthe jaws towards each other, one of the parts being slotted to form ofit a U-spring with the slot normally open, said toggle operative in atimed relation to the closing of the jaws to close the slot and thusmake the slotted part rigid by reason of the resistance imposed by thearticle to a further closing of the jaws when the toggle is in positionclose to but spaced from its fully distended portion, and said toggleoperative in moving more fully into its fully distended position totransmit power to the jaws to more fully close the same.

References Cited in the file of this patent UNITED STATES PATENTS 64,698Patterson May 14, 1867 543,665 Wright July 30, 1895 608,012 StricklerJuly 26, 1898 1,080,319 Benninghoff Dec. 2, 1913 (Other references onfollowing page) 7 UNITED STATES PATENTS Pae'keWitz et a1. May 26, 1914P'arrnelee Apr. 13, 1920 Bjorhli June 22, 1920 R6bi11s0T-f';- Dec. 29,1925 Jchnsofi June 26, 1928 Norwo'dd Apr. 9, 1929 Petersen Apr. 14, 1942Cropp Apr. 27, 1948 8 Thayer Feb. 28, 1950 Koskinen Dec. 12, 1950 OlsonNov. 6, 1951 Goodman Dec. 23,1952 Anderson et a1 Feb. 10. 1953 FOREIGNPATENTS Great Britain May 6, 1947

